When a PBA is inserted into a PBA module, it has up to now been necessary either to put the right board in the right place, i.e. each place is unique to a specific board, or to put a board in an arbitrary place and thereafter manually, e.g. by some form of programming, inform the system of what type of board that has been inserted and in what place this board has been inserted. Both of these methods require great care by the operator.